Spring Roo Internals Javaday IV

Massimiliano Dessì - SpringFramework Italian User Group

Javaday IV – Roma – 30 gennaio 2010

Spring ROOInternals and add-ons



SpeakerSoftware Architect / Developer

ProNetics / Sourcesense

Chairman JugSardegna Onlus

Founder SpringFramework Italian User Group

Committer - ContributorOpenNMS - MongoDB - MagicBox

AuthorSpring 2.5 Aspect Oriented Programming

http://www.pronetics.it/

http://www.sourcesense.com/

http://www.jugsardegna.org/

http://it.groups.yahoo.com/group/SpringFramework-it

http://www.opennms.org/

http://www.mongodb.org/

http://sourceforge.net/projects/magic-box

http://www.packtpub.com/aspect-oriented-programming-with-spring-2-5/book

http://www.pro-netics.com/

http://www.sourcesense.com/

http://it.groups.yahoo.com/group/SpringFramework-it

http://www.jugsardegna.org/

http://www.packtpub.com/aspect-oriented-programming-with-spring-2-5/book



Agenda- Demo for unbelievers-

- Roo Internals -

- Maven Roo support -

- Add On Anatomy -

- Roo Domain Driven Design -

- AspectJ Intertype Declaration -

- SpringSurf Add-on -



5 Minutes demo for Unbelievers

Demo for unbelievers

Roo Internals

Maven Roo support

Add On Anatomy

Roo Domain Driven Design

AspectJ Intertype Declaration

SpringSurf Add-on



Roo internals


Roo Internals

Maven Roo support

Add On Anatomy



SpringSurf Add-on



Classpath

ProcessManager

Shell Project

MetadataModelFile Undo File Monitor

Core modules

Support



Roo in its essence is an interactive shell

and a ProcessManager

The Shell receives the commands

and a ProcessManager

coordinates the operations

required from the user



- The Shell has a very good usability -

(tab, context awareness, hiding, hints)

- Background monitoring of externally-made changes -

- Full interaction with Spring Tool Suite -



Shell

The Shell

parses and validates the user input

and publishes the status about current task

STARTING, STARTED, USER_INPUT, PARSING, EXECUTING,

EXECUTION_RESULT_PROCESSING,

EXECUTION_COMPLETE, SHUTTING_DOWN



ProcessManager

The Shell passes the ParseResult object

to the execute method

of the ProcessManager

(Strategy pattern)



ProcessManager

ProcessManager delivers:

- State publication model -

- Polling on filesystem resources -

- Execute CommandCallbacks for requested operations -

- "Transaction-like" context for above operations -



Commands

During the bootstrap ROO

reads all bean classes

of type CommandMarker (Tag interface)



The Shell stores the metadata information

(@CliAvailabilityIndicator) read from

all CommandMarker beans

In this way the Shell knows all available commands

and MethodTarget related to user input



The Command class (CommandMarker)

uses the related Operations class.

The Operations class

performs the real work

on Java and AspectJ classes, XML and template files.



Maven ROO supportsometimes maven is your friend :)


Roo Internals

Maven Roo support

Add On Anatomy



SpringSurf Add-on



Roo uses Maven under the hood for:

building the entire project and managing dependenciesroo> project --topLevelPackage com.proj.roo.addon

add-on development roo> project --topLevelPackage com.proj.roo.addon --template ROO_ADDON_SIMPLE

eclipse / STSroo> perform eclipse

packagingroo> perform assembly



Add-On anatomySecurity add-on in the example


Roo Internals

Maven Roo support

Add On Anatomy



SpringSurf Add-on



@ScopeDevelopmentShell public class SecurityCommands implements CommandMarker{

private SecurityOperations securityOperations;

public SecurityCommands(SecurityOperations securityOperations) { Assert.notNull(securityOperations, "Security operations required"); this.securityOperations = securityOperations; }

@CliAvailabilityIndicator("security setup") public boolean isInstallSecurityAvailable() { return securityOperations.isInstallSecurityAvailable(); }

@CliCommand(value = "security setup", help = "Install Spring Security into your project")

public void installSecurity() { securityOperations.installSecurity(); } }



Security add-on

@ScopeDevelopmentShell public class SecurityCommands implements CommandMarker … public SecurityCommands(SecurityOperations securityOperations) { Assert.notNull(securityOperations, "Security operations required"); this.securityOperations = securityOperations; }

@ScopeDevelopmentShell : Indicates a class that should be instantiated when the ROO

development Shell is used.

CommandMarker : Tag Interface, the Command class must implement this interface



Commands @CliAvailabilityIndicator("security setup") public boolean isInstallSecurityAvailable() { return securityOperations.isInstallSecurityAvailable(); }

@CliAvailabilityIndicator:Annotates a method that can indicate whether a particular

command is currently available or not.

This annotation must only be applied to a public no-argument method that returns primitive boolean.

The method should be inexpensive to evaluate, as this method can be called very frequently. If

expensive operations are necessary to compute command availability, it is suggested the method

return a boolean field that is maintained using the observer pattern.



Commands

@CliCommand(value = "security setup", help = "Install Spring Security into your project")public void installSecurity() { securityOperations.installSecurity();}...

@CliCommand value: one or more strings which must serve as the start of a particular command in order to match this method (these must be unique within the entire application)

help: help message for this command (the default is a blank String, which means there is no help)



Operations

@ScopeDevelopmentpublic class SecurityOperations private FileManager fileManager; private PathResolver pathResolver; private MetadataService metadataService; private ProjectOperations projectOperations;

....

The SecurityOperations uses the above convenient Roo API to fulfill its purpose:- Find/write and read any resources (Java, XML, JSP, Properties, AJ) on filesystem- Read metadata- Handle the POM file



Recap, add-on should:

- Make a “Command” class and implement CommandMaker -

- Delegate methods through to an “Operations” object -

- Annotate methods with @CliCommand -

- Annotate method parameters with @CliOption -

- Optionally use @CliAvailabilityIndicator if desired -

- Throw any exceptions to abort and rollback changes -

- Use JDK logging or return objects for console output -



• Backup

• Bean Info

• Configurable

• Data On Demand

• Email

• Entity

• Dynamic Finder

• Java Bean

• JMS

• JPA

• Logging

• Maven

• Pluralization

• Property Editor

• Property File

• Security

• Integration Test

• ToString

• Web (various)

1.0.1 Base Add-Ons





Roo Internals

Maven Roo support

Add On Anatomy



SpringSurf Add-on



Roo uses a pragmatic design approach.

Following the Domain Driven Design principles,

Roo avoids

Anemic Objects and prefers Rich Domain Objects

that follows Object Oriented principles.

This means encapsulation, immutability and

proper role of domain objects



Do you

remember the

controller-entities

interaction

of this slide ?

Roo works in a

similar way

http://www.slideshare.net/desmax74/real-spring-aop-recipes-for-your-everyday-job-presentation



Roo by default uses two layers:

An entity layer (similar to domain layer)

and a web layer (REST).

Roo achieves separation of concern

of these two layers

through AspectJ ITD-based architecture.



- REST Controllers work directly with Domain entities -

- OpenEntityManagerInViewFilter -

- JPA EntityManager bound to the thread for the entire

processing of the request -

- allow for lazy loading in web views -

- original transactions already being completed -

- Service layer is optional, it can be created and used for business

logic spanning multiple entities -



AspectJ ITD(where Roo shines)


Roo Internals

Maven Roo support

Add On Anatomy



SpringSurf Add-on



Do you

remember

the concept

of

this slide ?

http://www.slideshare.net/desmax74/real-spring-aop-recipes-for-your-everyday-job-presentation



The Spring Introductions in the Aspect world

are called Inter-Type Declarations (ITD) .

Roo uses AspectJ ITD

instead of Spring Introductions (proxy based).

With ITD Roo performs active generation.



The ITD enables ROO through the add-on

to write the custom logic

into <name_class>_Roo_<addOn>.aj files

related to the corresponding java class

AspectJ compiler does the rest

by linking the pieces of the puzzle :)



For example the add-ons Entity, JavaBean, ToString

generates the proper logic in corresponding .aj files.

*_Roo_Entity.aj

*_Roo_JavaBean.aj

*_Roo_ToString.aj



With AspectJ ITD

Roo can implement

an effective Object Oriented

Domain Driven Design

application



Alfresco SpringSurf add-on


Roo Internals

Maven Roo support

Add On Anatomy



SpringSurf Add-on

http://www.springsource.org/extensions/se-surf



“Spring Surf is a view composition framework

for Spring MVC that plugs into

your existing Spring applications.

It provides

a scriptable and content-centric approach

to building web applications “



Surf is born from the alfresco community

need of a lightweight approach

to create application services

and

user interface extensions

instead of JSF or Struts



Spring Surf is an official

Spring extension by Alfresco.(http://www.springsource.org/extensions/se-surf)

Roo enables scaffolding for

Surf pages, templates and components.

http://www.springsource.org/extensions/se-surf



The Spring Surf Roo add-on

shows one of the many possibilities

that Roo provides with its API



Spring-Surf mini demo



Q & A



• Home• http://www.springsource.org/roo• Contains links to all other resources

• Forum• http://forum.springsource.org

• Issues• http://jira.springframework.org/browse/ROO

• Twitter• #roo hash key• follow @schmidtstefan & @benalexau

Project resources

http://jira.springframework.org/browse/ROO



Massimiliano Dessì desmax74 at yahoo.it

massimiliano.dessi at pronetics.it

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Thanks for the attention !

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Technology

Spring Roo Internals Javaday IV